Does voltage matter for an ammeter to work?

More specifically, would a 12-volt ammeter work with a 6-volt system?

A volt meter measures voltage and an ammeter measures current. In doing
measurements, they are independent. Therefore, your ammeter is not
voltage-dependent. There's no such thing as a 12-volt ammeter or a
6-volt ammeter. An ammeter will work regardless of the voltage in the
system. Just mind your polarities and make sure that your test leads
are large enough to handle the maximum current you intend to measure.

Regards,
scotty

"Masospaghetti" > wrote in message
...
> More specifically, would a 12-volt ammeter work with a 6-volt system?

Yes

Masospaghetti wrote:

> More specifically, would a 12-volt ammeter work with a 6-volt system?

Ayup, but you might want to check the amperage rating. for instance, a
12V generator might only put out 30 amps but a 6V one would put out 45.
That's still less power, but would peg a 30A ammeter and might not be
particularly good for it.

nate

--
replace "fly" with "com" to reply.
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On Thu, 03 Mar 2005 14:46:34 -0500, Masospaghetti > wrote:
>More specifically, would a 12-volt ammeter work with a 6-volt system?

Yes. Ammeters don't measure voltage.

However, what you really have is a voltmeter measuring the voltage drop
across a shunt. If you ran too high a voltage like trying to measure
the current through a 110vac device, you might find that shunt going
up in smoke.

There's no problem w/ using a ammeter designed for use on a 12V
system on a 6V system.

In article >,
TCS > wrote:
>On Thu, 03 Mar 2005 14:46:34 -0500, Masospaghetti
> wrote:
>>More specifically, would a 12-volt ammeter work with a 6-volt system?
>
>Yes. Ammeters don't measure voltage.
>
>However, what you really have is a voltmeter measuring the voltage drop
>across a shunt. If you ran too high a voltage like trying to measure
>the current through a 110vac device, you might find that shunt going
>up in smoke.

[Pedant mode on]
A digital multimeter might use a voltage measurement on a shunt, but if
the meter has a movement, an ammeter directly measures the force produced
by the magnetic field of the current and a voltmeter is an ammeter in
series with a known, large resistance. An ohmmeter is a known voltage
in series with an ammeter that measures the current through the unknown
resistance, or why the needle moves more for smaller resistances.
>
>There's no problem w/ using a ammeter designed for use on a 12V
>system on a 6V system.

Just make sure that the meter can handle the max current that can possibly
happen.

TCS wrote:
>
> On Thu, 03 Mar 2005 14:46:34 -0500, Masospaghetti > wrote:
> >More specifically, would a 12-volt ammeter work with a 6-volt system?
>
> Yes. Ammeters don't measure voltage.
>
> However, what you really have is a voltmeter measuring the voltage drop
> across a shunt.

The ammeter on my old Ford tractor just ran the main power
feed through a loop on the back of the ammeter. I assume the
"loop" was really a coil of some type. And that the current
flowing in the main feed wire induced a voltage in the loop
that operated the needle. Not sure how it worked, but it
did.

Ed

The loop was likely a piece of metal that had a calibrated resistance,
across which the ammeter movement was connected to measure the voltage
drop created by the resistance. This is most common in automotive
ammeters. The loop is the "shunt."

Dan

Masospaghetti wrote:

> More specifically, would a 12-volt ammeter work with a 6-volt system?

As you have read, ammeters handle current in amperes. Make sure the
ammeter can handle the maximum current flow through it.

HOWEVER, if there is an illumination light bulb in the ammeter for night
time viewing, make SURE it is of the appropriate (6 or 12) voltage.

> wrote in message
ups.com...
> The loop was likely a piece of metal that had a calibrated resistance,
> across which the ammeter movement was connected to measure the voltage
> drop created by the resistance. This is most common in automotive
> ammeters. The loop is the "shunt."
>
> Dan


No.. The loop was a coil (one turn often) which created a magnetic field
which moved the iron vane attached to the pointer. Very simple, very
cheep but worked.

Why would you try to generate a voltage to drive a voltmeter which after
all is only a high resistance amp meter, when the simple amp meter is so
much cheaper, and inserts less voltage drop in the circuit than any
shunt.
--
John G

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